ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 707 



two of the cells become larger, and a more advanced type of cortex 

 results. (:->) A true cortex is formed by the terminal cells of these 

 hypha; becoming rounded off as well as larger and by sending out 

 short branches, the whole forming a kind of plectcnchyma. The 

 development of the fruits is also traced, and detailed descriptions given 

 of five new species and of several varieties. 



Cladonias in the Islands of the North Sea.* — M. Sandstede 



follows Nylander and Wainio in his study of this lichen genus. In the 

 introduction he gives the characters which distinguish the species and 

 forms of the genus. Each species is described and critically compared 

 with the plants from the different exsiccatse. The islands proved to be 

 less rich in species than the mainland, but several additions were made 

 to the flora, and three new varieties are described. 



Notes on Cladonia.f — Bruce Fink continues his descriptive and 

 critical notes on American species of Cladouia. He finds that Gladonia 

 subcariosa differs from CI. cariosa in having larger sqnamules and less 

 fissured and carious podetia. CI. mitrula and CI. leptophylla, which are 

 also passed under review, are very near to each other, but are dis- 

 tinguished by the smaller squamules and podetia of the latter. They 

 both grow usually on soil. 



"Chemical Tests" in Determining Lichens. $ — The late Dr. 

 "William Nylander found that the tissues of lichens reacted differently, 

 according to the species, to the application of various chemical solutions. 

 These were chiefly potassium hydrate and calcium hypochlorite. Since 

 his day, opinions have differed as to the diagnostic value of these tests. 

 G\ K. Merril sums up the evidence for and against their employment. 

 Most of the American lichenologists have pronounced against their use. 

 Merril himself considers them of great use in the determination of 

 species, and in this matter he is in harmony with workers on the 

 Continent at the present day. 



Eeichseb, E. — Beitrage zur Flechtenflora der Umgegend von Hamburg und 

 Holsteins. (Contributions to the lichen flora of the neighbourhood of Hamburg 

 and Holstein.) 



[The list includes 300 species from a somewhat small area.] 



Verh. Nat. Ver. Hamburg, xiii. (1905) pp. 44-104. 



See also Ann. My col, iv. (1906) p. 380. 



Heree, A. W. C. T.— The Foliaceous and Fruticose Lichens of the Santa Cruz 



Peninsula, California. Proc. Wash. Acad. Sci., vii. (1906) pp. 325-96. 



See also Ann. Mycol, iv. (1906) pp. 380-1. 

 Hesse, O.— Beitrag zur Kenntnis der Flechten und ihrer charakteristischen Bes- 

 tandteile. (Contribution to the knowledge of lichens and of their characteristic 

 constituents.) 



[A study of the chemical constitution of Usnea, Alcctoria, Cetraria, and 



others.] Journ. Prakt. Chemie, n.f. lxxiii. (1906) pp. 113-76 



See also Ann. Mycol, iv. (1906) pp. 381-2_ 



Howe, Reg. Hebe r. 3 vs. — Lichens of Mount Monadnock, New Hampshire. 



!"A list is given of 71 species, with the habitat.] 



Amcr. Nat., xl. (1906) pp. 661-5. 



* Abh. Nat. Ver. Bremen, xviii. (1906) pp. 384^56 (4 pis.). See also Bot' 

 Centralbl., cii. (1906) pp. 121-2. 



t Bryologist, ix. (1906) pp. 57-60 (1 pi.). % Tom. cit. pp. 60-71. 



